Application of GIS and remote sensing in land use zoning: case study: Turkana County

Abstract

Turkana County is a County in Kenya which spans 71,597.8 km² making it the largest County in Kenya and has a population of approximately 855,399 (Government of Kenya, 2010). It is bordered by the countries of Uganda to the west, South Sudan to the North, Ethiopia to the Northeast, and Lake Turkana to the East. Neighbouring counties in Kenya are West Pokot to the South West, Baringo to the South and Samburu to South East. It is bound between latitudes 0.90 N and 5.50 N and longitudes 340E and 370E. The project aimed at the development of land use zones for Turkana County with the use of remote sensing and Geographical Information Systems (GIS) technologies. Spatial Multi-criteria Decision Analysis (MCDA) is a proven method for land-use planning purposes. However, most land-use planning applications focus on a specific theme, such as urban development and are often limited to a relatively small area. As the project area was really large in size, 71,597.8 km², the approach used was with reference to the Land-Use Conflict Identification Strategy (LUCIS) model, which was developed at the University of Florida in The United States of America. Criteria to be used for the suitability analysis were designed to suit the Turkana area and this resulted in the identification of data to be used, that is, land cover, rainfall, slope and lithological formation. Four main land-use zones, that can support urban and settlement areas, rain fed agriculture, irrigated agriculture and livestock were then identified. Stakeholder’s involvement was realized by assigning weights to the goals and resulting preference maps. The Analytical Hierarchy Process (AHP) was used as the weighting method to assign weights to the objectives identified for the zones of interest. Suitability maps for the four zones were then created. Finally, the suitability maps of the three land-use categories were combined, in order to visualize conflict areas. In conclusion, Turkana County has the potential to support urban and settlement areas, rain fed agriculture, irrigated agriculture and livestock and this could be implemented on the ground.